If you were about to buy a new case of Amsoil for your bike would you pick Amsoil 10W40 or Amsoil 15W40. Would the 15W40 hold up better in my little VFR? Seems to me the 15w40 would have fewer polymers in it to shear.

I haven't ran any Amsoil in it yet. Only Rotella 5W40 and it has worked well for nearly 4K. Shifting is just now getting clunky.

I think you might have picked an excellent choice with the 15w40, I think thats what I would pick. I will note that in my past experience that I have had the best shifting when I used yamalube in the odd 20W40 in my motorcycle. I am going to use the yamalube for the 05 riding season because of its shifting qualities.

I haven't waded through all of the 'wet-clutch' issues, as my BMW has a dry clutch. I believe wet-clutch bikes should have non friction modified oil (motorcycle oil), but there are plenty of bikers that don't subscribe to that.I decided on Amsoil 20w50 (ARO) in the summer and Amsoil 10w40 (AMO) in the winter.

quote:Originally posted by KW: If you were about to buy a new case of Amsoil for your bike would you pick Amsoil 10W40 or Amsoil 15W40. Would the 15W40 hold up better in my little VFR? Seems to me the 15w40 would have fewer polymers in it to shear.

If I didn't care about warranty or JASO MA and I wanted the best synthetic at the best possible prices and I didn't ride below 32 degrees very often, then I would use the Amsoil 15w40 AME.

Bar none it's the best synthetic at a very attractive price. It is used as the same formulation as the 10w40 and 20w50 it contains no friction modifiers. I don't know if it meets JASO MA because it isn't listed on the label. But 2 years ago I was confirmed by Amsoil tech support that it contained no friction modifiers.

For me, I keep it simple becuase I sell the products and recommend them, it seems easier for me to explain to a customer to use the Motorcycle Specific stuff. Therefore that is what I use in the bikes. Also I use the 10w40 in my Diesel TDI, so I can keep my lubricants consolidated to the 10w40 and the 10w30 for my F150.

But by all means. I really think the 15w40 AME is the best bang for the buck.

quote:Originally posted by drive it forever: I think you might have picked an excellent choice with the 15w40, I think thats what I would pick. I will note that in my past experience that I have had the best shifting when I used yamalube in the odd 20W40 in my motorcycle. I am going to use the yamalube for the 05 riding season because of its shifting qualities.

I think if you try the Amsoil 10w40 or the 15w40(though I'm not technically "recommending" it)you will find awesome shift quality over the life of the drain interval.

I put 6,000 on my last drain of the Amsoil 10w40 in my 02 triumph sprint ST. Shifting stayed the same over the entire drain. I ran Delo for a short breakin change of 1500 miles ( I was shooting for 2,000) but couldn't stand the shift quality after 1500 miles.

BTW, Amsoil has a distribution center now in columbus. Hope this helps.

Thanks for the information. I have a couple more oil changes left for the bikes, but next time around I might try the 15W40 in the VFR. My brothers Bandit 1200 is picky about oil and the 10W40 works well in it. It might end up being a coin toss at ordering time because both bikes need to run the same oil. I keep track of the oil for both bikes.

I sent an email to Amsoil and they told me that the 10W40 automotive and motorcycle oils are the same product and packaged different for marketing purposes. They told me that the 10w40 has no friction modifiers and will meet the JASO MA rating, but it wasn't on the bottle yet. Since then I saw a bottle of 10W40 and I think it says JASO MA on it now. I don't know about the 15W40, but I would suspect it is the same. I've also heard good things about the Yamalube 20W40, but it must be hard to start in the cold weather.

Run the 20W50. The side mounted radiators on the VFR don't do well in transfering heat under 40 mph, and thus the bike runs too hot. A real common complaint years ago when they were raced. I have a 2000 VFR (the great and only yellow one), and it seems to shift better with the 20W50, even in the cold. I'll ride down to about freezing, and many of my rides are 300 to 400 mile days. No problems, and the motor is quieter to boot with the heavier oil.

I'm probably the only one on this site that had his clutch slip with Amsoil 15W40 (AME). Bandit 12S; had 3500 miles on the clock. I had a few gallons sitting around and really thought I was doing my bike a good thing.

I have to admit that the engine ran great, idled faster and smoother, but couldn't loft the front end with that oil. Clutch just couldn't hook. That was my first indication that the clutch was slipping.

My Honda 750 liked M1, if thats any consolation.

I'll continue to use AME in the Cummins, the 'Stang, and probably the lawn mowers, but it won't see the inside of my little road burner.

quote:Originally posted by Stooge: Run the 20W50. The side mounted radiators on the VFR don't do well in transfering heat under 40 mph, and thus the bike runs too hot. A real common complaint years ago when they were raced. I have a 2000 VFR (the great and only yellow one), and it seems to shift better with the 20W50, even in the cold. I'll ride down to about freezing, and many of my rides are 300 to 400 mile days. No problems, and the motor is quieter to boot with the heavier oil.

Interesting. The only time mine has notchy shifting is when the motor is good and warm. I'll keep this in mined.